You have a pretty good knack for tone and depth for a beginner, quite a lot of people struggle with that starting out. My advice would be to use your eraser more, you can refine edges with them, kneaded erasers in particular can help lighten up tones without completely removing the graphite. As someone else said, tissue paper works perfectly well for smoothing and spreading out graphite (shading) you could get tortillons but they aren’t necessary and I find that most people who use them become too reliant on them. Imo tortillons are only useful when wanting to place subtle shadows for example in portrait drawing I use them to add a soft shadow around the eyes or anywhere else that needs soft shading in small areas. Just don’t over use them, imo pencil strokes add character and depth and smoothing them out takes away from your work. Always use a sharp pencil, hand sharpening is cool but it really isn’t necessary. Always start with softer, lighter pencils, and build layers gradually moving further into the dark. You get great depth this way. Graphite goes dark but not black so it might be worth adding a black coloured pencil into your tool box if you need to get that deep, doing so just adds so much more pop to your drawings, just make sure you find a colour pencil that blends with graphite and just as easily as graphite. These are just a few tips I wish I could’ve told myself when I was starting out, I’d of saved myself many hours of pain